Cervical stenosis with spinal cord compression and consequent myelopathy is a very common problem encountered by the spine surgeon. The usual cause of multilevel cervical stenosis is spondylosis and/or ossification of the posterior longitudinal ligament. Surgical decompression either through an anterior or posterior approach can be undertaken.
An anterior approach usually involves multilevel corpectomy with fusion and stabilization. The main drawback of this technique is the increased time and complexity of the procedure as well as the risk of pseudoarthrosis and accelerated degeneration at the levels above and below the fusion.
A posterior approach has traditionally involved a simple laminectomy, laminectomy with facet fusion, or laminoplasty. The drawback of a simple laminectomy is the risk of late clinical deterioration form either kyphosis or postlaminectomy scar formation. Laminectomy with facet fusion decreases the risk of kyphosis but it also decreases the range of motion in the spine and increases the risk of accelerated degeneration at the levels above and below the fusion.
Laminoplasty either through open door or double door technique provides greater stability and range of motion when compared with laminectomy alone. This technique entails laminoplasty for decompression and fixation with a plate with or without laminar fusion. The principle behind laminar fixation is that it maintains the decompression following laminoplasty as well as the displaced lamina in a fixed position thereby providing stabilization also.
U.S. patent application Ser. No. 10/035,281 describes several laminar fixation plates with and without a bone fusion spacer that allow for lamina fixation and/or fusion. U.S. Pat. No. 6,660,007 describes laminoplasty plates for open door and double door techniques with a spacer in the middle to maintain the decompressed lamina position.
The present invention is an apparatus for use in either the open door or double door laminoplasty technique to stabilize the lamina in the spine thereby preserving the range of motion as well as maintaining stability.